Clinical Policy: Homocysteine Testing
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Defines medical necessity and not‑medically‑necessary indications for homocysteine laboratory testing for members/enrollees of health plans affiliated with Centene Corporation (Arizona Complete Health). Affects ordering providers and billing for serum/urine homocysteine tests.
No material clinical or coverage changes in this revision.
Coverage Criteria
inv-01: Medically Necessary: Suspected Homocystinuria
Covered when ANY of the following specific criteria for suspected homocystinuria are met:
From policy section I
inv-02: Not Proven to Improve Outcomes / Not Medically Necessary for Listed Indications
Testing is considered not proven to improve outcomes for the following indications:
From policy section II
The ICD-10 codes listed in the Not Medically Necessary ICD-10 Codes table are excluded from coverage for homocysteine testing unless an exception is specifically noted elsewhere in this policy. Claims submitted with those diagnosis codes may be denied if they do not meet a documented exception supporting medical necessity.
When coverage provisions in this clinical policy conflict with applicable state Medicaid requirements, state Medicaid coverage provisions take precedence. Providers should consult the state Medicaid manual for any state-specific coverage rules that apply to homocysteine testing; similarly, Health Plan coverage decisions remain subject to the terms, conditions, exclusions and limitations of the applicable coverage documents.
Examples of indications considered not medically necessary include: cardiovascular risk assessment; evaluation of borderline vitamin B12 deficiency when used alone; dementia screening or cognitive decline assessment; and use for venous thromboembolism (including idiopathic/unprovoked VTE, recurrent VTE, thrombosis occurring at <45 years of age, or thrombosis at an unusual site). These indications are listed in the policy because evidence does not show that homocysteine testing improves clinical outcomes for these uses.
Covered Indications
inv-21: Evaluation for suspected homocystinuria (cystathionine beta-synthase deficiency)
From laboratory covered indications
inv-22: Covered Indications
Placeholder: see policy for any plan‑specific exceptions
Coding
| 83090 | Homocysteine |
| F01.511 | Vascular dementia, unspecified severity, with agitation |
| F01.518 | Vascular dementia, unspecified severity, with other behavioral disturbance |
| F01.52 | Vascular dementia, unspecified severity, with psychotic disturbance |
| F01.53 | Vascular dementia, unspecified severity, with mood disturbance |
| F01.54 | Vascular dementia, unspecified severity, with anxiety |
| F01.A4 | Vascular dementia, mild, with anxiety |
| F01.B4 | Vascular dementia, moderate, with anxiety |
| F01.C4 | Vascular dementia, severe, with anxiety |
| F03.9 | Unspecified dementia, unspecified severity |
| F03.A4 | Unspecified dementia, mild, with anxiety |
Provider Actions & Billing
Billing code: CPT 83090 for homocysteine
Report homocysteine testing using CPT code 83090 (Homocysteine) as referenced in the policy.
Prior authorization — follow plan documents
Check the member's Health Plan coverage documents and administrative policies for any prior authorization requirements before ordering or submitting claims; the clinical policy defers to plan documents for authorization rules.
Step therapy requirements
There are no step therapy requirements specified in this clinical policy for homocysteine testing.
Follow policy criteria and plan requirements
When ordering and submitting claims, providers must follow the coverage policy criteria and administrative requirements outlined in the Health Plan's coverage documents.
- Ensure orders and claims align with the clinical criteria for medically necessary testing (see policy section I).
Required clinical documentation to support medical necessity
Include clinical documentation that supports suspected homocystinuria when requesting or billing for testing: family history of homocystinuria, markedly elevated serum or urine homocysteine, or characteristic physical findings (developmental delay; marfanoid appearance; osteoporosis; ocular abnormalities such as ectopia lentis; thromboembolic disease; or severe premature atherosclerosis).
Submit claims per Health Plan coverage documents
Adhere to the Health Plan's coverage documents (e.g., evidence of coverage, certificate of coverage, policy) when submitting claims; coverage decisions and administration of benefits are subject to the terms, conditions, exclusions, and limitations of those documents.
- The Health Plan may change or withdraw the clinical policy; verify current plan documents prior to submission.
Denial risk for tests ordered for not‑medically‑necessary indications
Claims for homocysteine testing submitted for indications listed as not proven to improve outcomes (for example: cardiovascular risk testing; borderline vitamin B12 deficiency; dementia; idiopathic or recurrent VTE; thrombosis <45 years or at unusual sites) or for ICD-10 codes listed as Not Medically Necessary may be denied.
Coverage subject to plan terms, exclusions, and state requirements
Coverage decisions and the administration of benefits are governed by the Health Plan's coverage documents and are subject to their terms, conditions, exclusions, and limitations; state Medicaid provisions take precedence if in conflict.
Ordering Requirements
Ordering requirements: document clinical criteria
No specific ordering provider type restrictions are stated; however, clinical criteria supporting medical necessity for suspected homocystinuria must be documented.
Provider responsibility and judgment for ordering
Providers are expected to exercise professional medical judgment when ordering homocysteine testing; the policy does not impose specific restrictions on which provider types may order the test.
Frequency Limits
Not Covered
Homocysteine testing is not covered when performed solely for cardiovascular risk assessment, as randomized trials and systematic reviews have not demonstrated that lowering homocysteine reduces cardiovascular events. Testing is also not covered as the sole test for borderline vitamin B12 deficiency (MMA is preferred), for routine dementia screening, or for evaluation of idiopathic or recurrent venous thromboembolism (VTE), including thrombosis at young age (45 years) or at unusual sites.
No explicit additional exclusions for specific laboratory tests or indications beyond those identified in the policy text are listed in the provided document excerpt. Providers should refer to the full coverage documents and state-specific guidance for any plan-level exclusions not contained in this policy.
Background
Homocysteine is an intermediate amino acid in the conversion of methionine to cysteine via remethylation and transsulfuration pathways. Markedly elevated plasma or urine homocysteine concentrations characterize homocystinuria, a rare inherited disorder most commonly due to cystathionine-β-synthase deficiency. Clinical features that suggest homocystinuria include developmental delay, a marfanoid habitus, osteoporosis, ocular findings such as ectopia lentis, thromboembolic disease, and severe premature atherosclerosis.
Definitions
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